C++链接问题

[huangzhtao]

想写一个建立二叉树的类,只写了构造函数,编译就出现了以下问题:
1>BiTree.obj : error LNK2019: unresolved external symbol "public: struct tree * __thiscall biTree::create_btree(struct tree *,struct tree *,char)" (?create_btree@biTree@@QAEPAUtree@@PAU2@0D@Z) referenced in function "public: __thiscall biTree::biTree(char *,int)" (??0biTree@@QAE@PADH@Z)

全部编译结果如下:
1>------ Build started: Project: BiTree, Configuration: Debug Win32 ------
1>Compiling...
1>BiTree.cpp
1>g:\c++class\bitree\bitree.cpp(111) : warning C4715: 'create_btree' : not all control paths return a value
1>Linking...
1>BiTree.obj : error LNK2019: unresolved external symbol "public: struct tree * __thiscall biTree::create_btree(struct tree *,struct tree *,char)" (?create_btree@biTree@@QAEPAUtree@@PAU2@0D@Z) referenced in function "public: __thiscall biTree::biTree(char *,int)" (??0biTree@@QAE@PADH@Z)
1>G:\C++Class\BiTree\Debug\BiTree.exe : fatal error LNK1120: 1 unresolved externals
1>Build log was saved at "file://g:\C++Class\BiTree\BiTree\Debug\BuildLog.htm"
1>BiTree - 2 error(s), 1 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
代码如下:

#include<iostream>
#include <string>
#include<stdio.h>

using namespace std;

struct tree {                          

    char info;                           

    struct tree *left,*right;            

};


class biTree
{
public:
	biTree(char *s, int n );
	~biTree();

	struct tree *create_btree(struct tree *root,struct tree *r,char info);

	void InOrder(struct tree *T);           //中序递归遍历二叉树

	
private:
	struct tree  *root;
};

//******************************************

// the main function 

//******************************************

int main()

{   

	return 0;

}  


biTree::biTree(char *a, int n )
{                  
    root = '\0';       
	char *s;
	s = a;

    do { 
		s = a;
		n--;
		
		if (!root){

			root=biTree::create_btree(root,root,*s);
		}

		else{

			//create_btree(root,root,*s);
		}
		a++;
      }  while ( n ) ;
}

struct tree biTree::*create_btree(struct tree *root,struct tree *r,char info)

{  
	if (r ==0 )
	{
		r=new (struct tree);

		if ( r == 0)

		{  
			printf("Out of memory\n");
			return 0 ;
		}

		r->left= 0;
		r->right=0;
		r->info=info;

		if (root)
		{
			if(info<root->info)    root -> left=r;

			else   root->right=r;

		}

		else
		{
			r->right=0;
			r->left = 0;
		}

	}    

	if (info < r->info)

	create_btree(r,r->left,info);

	if(info>=r->info)

	create_btree(r,r->right,info);

} 

网上找了,没找到解决办法.各位大哥帮忙看下,谢谢了!

[baihacker]

struct tree* biTree::create_btree(struct tree *root,struct tree *r,char info)
//*号写错地方了

[babyvox1999]

struct tree biTree::*create_btree(struct tree *root,struct tree *r,char info)
--------------------------------
struct tree* biTree::create_btree(struct tree *root,struct tree *r,char info)

[huangzhtao]

问题解决了,太感谢了,接分吧!

[tgh621]

struct tree biTree::*create_btree(struct tree *root,struct tree *r,char info)
改为
struct tree* biTree::create_btree(struct tree *root,struct tree *r,char info)

[p0303230]

[Quote=引用 4 楼 tgh621 的回复:]
struct tree biTree::*create_btree(struct tree *root,struct tree *r,char info)
改为
struct tree* biTree::create_btree(struct tree *root,struct tree *r,char info)
[/Quote]